This invention relates in general to devices that facilitate the securement of selected bones of the human body to one another in surgical procedures. In particular, this invention relates to an improved structure for a cervical plate assembly that facilitates the fusion of two or more cervical vertebrae in an orthopedic surgical procedure by quickly and easily causing the vertebrae to exert a preloading force against a bone graft interposed therebetween. This invention also relates to an improved structure for a cervical plate assembly that facilitates the installation of the cervical plate assembly in an orthopedic surgical procedure by providing both a locking mechanism that positively retains one or more fasteners thereto and a viewing window that results in an unobstructed view of the vertebrae and the bone graft.
Many surgical procedures involve the securement of selected bones of the human body to one another. For example, when a spinal disc is removed from between two vertebrae in a spine (usually as the result of injury or degradation over time), a cervical spinal fusion procedure may be performed to secure the vertebrae together to prevent any relative movement from occurring therebetween. Such a cervical spinal fusion procedure typically involves the insertion of a bone graft in the space between the vertebrae that was previously occupied by the spinal disc. The bone graft fills the space left by the removed spinal disc and promotes the fusion of the vertebrae, a process that creates one continuous bone surface and eliminates motion at the fused joint.
After the bone graft has been inserted between the vertebrae, it is important to fix the spacing and alignment of such vertebrae relative to one another to allow the fusion process to occur. Such fixation is frequently accomplished by one or more cervical plates. A typical cervical plate is a rigid structure having first and second portions that are respectively secured to the two vertebrae after the bone graft has been inserted therebetween. Each of the first and second portions of the cervical plate is secured to its associated vertebra by one or more bone screws or other releasable fasteners. In this manner, the cervical plate rigidly engages the vertebrae to prevent any relative movement from occurring therebetween while the fusion process occurs.
A variety of cervical plate structures are known in the art and function satisfactorily. However, it is known that the fusion process can be facilitated by causing the vertebrae to exert a preloading force against the bone graft interposed therebetween. Thus, it would be desirable to provide an improved structure for a cervical plate assembly that facilitates the fusion of cervical vertebrae by quickly and easily causing the vertebrae to exert a preloading force against the bone graft interposed therebetween. It would also be desirable to provide an improved structure for a cervical plate assembly that facilitates the installation of the cervical plate assembly by providing both a locking mechanism that positively retains one or more fasteners thereto and a viewing window that results in an unobstructed view of the vertebrae and the bone graft.